1. Field of the Invention
The present invention relates to a driving controlling method for an image sensing device and an imaging device, adopted in an imaging system, monitoring system, etc. oriented for the factory automation (FA) to image, for example, an object moving at a high speed.
2. Description of the Related Art
In the imaging devices for FA and monitoring, rapid extraction of only video information has been attained in the past by transferring an unnecessary signal at a high rate to sweep them away while transferring a necessary signal at a normal rate for processing them as valid pixels. This is called “high-rate function”, for example. To have the imaging device as a camera with the high-rate function, it is necessary to enter a reference signal indicative of a start point of a rapid-transfer period and also a control signal indicating that the imaging device is operating in the rapid-transfer period.
The Applicant of the present invention proposed an image sensing device driving controlling method, imaging device, imaging controlling apparatus and imaging system, in which valid charges falling within a predetermined imaging range can be acquired as video signals by capturing images with a high-speed random shutter synchronized with a trigger signal by controlling the effective charge storage time of a solid-state image sensing device (CCD image sensor) of an interline transfer (IT) type (see the Japanese Patent Application Laid Open No. 191177 of 1998, for example).
In the imaging system, an image charge stored in each of a plurality of light-receiving elements in the IT type solid-state image sensing device is read to vertical transfer units in response to a charge read signal of a predetermined timing based on the trigger signal, the image charges read to the vertical transfer units are vertically transferred at a high rate synchronously with a vertical sync pulse and then read as image signal from the vertical transfer units via a horizontal transfer unit at a normal transfer rate synchronous with a horizontal sync signal. In this imaging system, valid charges falling within an arbitrary imaging range can be acquired as image signals by setting a rapid-transfer period to change the number of lines outputted as image signals.
When it is desired to extract a certain horizontal image from a valid image output, the image has been extracted in the past via a memory 103 as in an imaging device 100 shown in FIG. 1. More specifically, in the imaging device 100, an image signal (So) read from a CCD image sensor 101 in response to horizontal transfer clocks (H1, H2) synchronous with a horizontal sync signal (HD) supplied from a timing generator 104 is digitized by an analog-digital converter 102, and all valid image data (Do) are written once into the memory 103. When reading image data from the memory 103, only necessary horizontal image data (Da) is read according to a horizontal blanking signal (HBLK) supplied from the timing generator 104, as in a timing diagram shown in FIG. 2.